a. Field of Invention
The invention relates generally to improvements in pump dispensers, and more particularly to such pump dispensers having an improved inlet valve assembly for enabling a valve to properly seat against its valve seat for quick shut-off of the inlet port, especially when used with personal care products including “beads” containing fragrances, medicine, skin nutrients and other additives.
b. Description of Related Art
The known manually actuated pump dispensers especially those designed for the dispensing of personal care products which may be in the form of pastes, gels or other viscous products, typically have both inlet and outlet check valves for respectively controlling the flow of liquid product into the pump chamber during each piston suction (i.e. return) stroke and for controlling the outflow of the liquid product from the pump chamber during each piston compression (i.e. pressure) stroke. Such pump dispensers are advantageous in that they permit dispensing of products in a metered quantity over an extended period of use.
While such pump dispensers may operate adequately with typical viscous products having a uniform consistency, for a new type of personal care product which includes “beads” containing fragrances, medicine, skin nutrients and other additives, conventional pump dispensers have several drawbacks. Optimally, a pump dispenser for dispensing a personal care product containing beads would discharge a metered dose of the product, whereby a user can rub the product between his/her hands to thus frictionally break the beads and release the additives therein. The discharging of a metered dose of liquid product is essential, because the beads, which are of a predetermined size and contain a measured quantity of fragrances, medicine, skin nutrients and other additives, are intended to be discharged with a predetermined amount of liquid product to produce a desired end result. For example, in order to produce the desired degree of anti-bacterial cleansing, a 0.1 ounce metered dose of product may be required to include a minimal 5-to-1 liquid product-to-bead ratio. Thus, for the example provided above, a pump dispenser would be required to discharge a 0.1 ounce metered dose of product, and would further be required to ensure a minimal 5-to-1 liquid product-to-bead ratio. Any significant variation from the noted exemplary amounts would compromise the degree of anti-bacterial cleansing and render the pump dispenser inadequate for the intended purpose.
As a further example, referring to FIG. 5 of the present application, a related pump dispenser 10 is illustrated and includes an accumulator (i.e. pump cylinder) 12 having a valve seat 14 designed to retain ball check valve 16. During the discharge head pressure stroke, valve area 18 including guide ribs 20 is designed to guide ball check valve 16 into engagement with valve seat 14 to close inlet port 22. Further, during the discharge head return (i.e. suction) stroke, guide ribs 20 are designed to guide ball check valve 16 out of engagement with valve seat 14 to allow liquid product to by-pass ball check valve 16 between adjacently disposed ribs 20 and be dispensed out through an outlet port (not shown).
In use however, during successive pressure and return strokes, the relatively supple beads 24 disposed in the midst of liquid product 26 tend to accumulate below ball check valve 16 as illustrated in FIG. 5, and thereby interfere with valve 16 from properly seating against its seat 14. Thus after sufficient accumulation, the ensuing pressure stroke results in liquid product 26 collected in accumulator 12 returning to the container (not shown) via dip tube 28. As is well realized in the industry, such product return must be avoided to prevent contamination of unused product disposed in the container. Further, since the internal volume of accumulator 12 is designed to provide a metered dose of liquid product, any return of product to the container results in a less-than metered dose, which is undesirable. Yet further, as discussed above, since the discharged product is required to have a predetermined liquid product-to-bead ratio, accumulation of beads 24 below ball check valve 16 can increase or decrease the required liquid product-to-bead ratio, thus resulting in an unintended dosage of fragrances, medicine, skin nutrients or other additives in ratio to the liquid product.
Referring now to the related-art pump dispensers of U.S. Pat. No. 1,892,649 ('649 Patent), U.S. Pat. No. 2,589,581 ('581 Patent), U.S. Pat. No. 2,354,255 ('255 Patent), U.S. Pat. No. 3,498,315 ('315 Patent), U.S. Pat. No. 3,741,243 ('243 Patent), U.S. Pat. No. 4,705,195 ('195), U.S. Pat. No. 5,850,948 ('948), U.S. Pat. No. 6,508,269 ('269) and U.S. Pat. No. 6,668,856 ('856), while the pump dispensers and ball valves of the noted U.S. Patents are well known in the industry, none of the aforementioned U.S. Patents is known as being directed to addressing the aforementioned exemplary problems associated with personal care products including beads such as 24.
For example, as illustrated in FIG. 1 of the '649 Patent, a ball check valve 4 is provided and includes guide ribs 5-5 for guiding the valve to its seat 6 (Page 1:22-25). A removable plug 7 is provided for limiting upward travel of ball check valve 4, and for further enabling cleaning and/or replacement of valve 4 and valve seat 6, (Page 1:38-43). In this manner, the '649 Patent achieves the object of readily disassembling the valve parts for repair without dismounting the associated pipe connection, (Page 1:8-11). Thus, while the '649 Patent provides a removable plug 7 for accessing and cleaning ball check valve 4 and valve seat 6, and further provides guide ribs 5 for guiding movement of valve 4, the check valve assembly of the '649 Patent fails to recognize, much less solve, the aforementioned exemplary problems associated with personal care products including beads such as 24.
Similarly, as illustrated in FIG. 1 of the '255 Patent, a ball check valve 7 is provided and includes guide ribs 8 for guiding the valve to its seat 4 (Col. 1:42-46-Col. 2:9-11). Ribs 8 are provided for guiding valve 7 between its open and closed positions, and further permit free flow of fluid, (Col. 2: 11-15). Ribs 8 include a rounded lip 9 against which ball check valve 7 rests in its open position, thus preventing valve 7 from sticking in its open position, (Col. 2:15-21). Thus, while the '255 Patent achieves its object of using the ribs to permit free passage of fluid and preventing ball check valve 7 from locking in its open position, as discussed above for the '649 Patent, the check valve assembly of the '255 Patent likewise fails to recognize or solve the aforementioned exemplary problems associated with personal care products including beads such as 24.
Turning to the '243 Patent, the check valve illustrated in FIG. 1 includes ball check valve 30 movably disposed in cylindrical portion 26, (Col. 1:58-59). For flow of liquid in the direction of arrow 36, ball check valve 30 is disposed in the FIG. 1 configuration and liquid flows through valve 10 as illustrated, (Col. 2:1-4). This flow path provides a large cross-sectional flow path to prevent solid particles from becoming trapped in the valve assembly, and obstructing the flow path, (Col. 1:5-13). Thus while the '243 Patent achieves its object of unrestricted flow for liquid containing solid particles by providing an enlarged flow path, as discussed above for the '649 and '255 Patents, the check valve assembly of the '243 Patent likewise fails to recognize or solve the noted exemplary problems associated with personal care products including beads such as 24.
The remaining '581, '315, '195, '948, '269 and '856 Patents, which provide exemplary features such as adequate ball valve guidance, nevertheless fail to solve, much less recognize, the drawbacks of conventional check valves when used with personal care products including beads such as 24.
It would therefore be of benefit to provide a pump dispenser having an improved inlet valve assembly for enabling a valve to properly seat against its valve seat for quick shut-off of the inlet port, especially when used with personal care products including beads containing fragrances, medicine, skin nutrients and other additives. It would also be of benefit to provide a valve assembly which facilitates simple and economical manufacture and assembly of the pump dispenser, which is reliable in operation to provide a desired liquid product-to-bead ratio while enabling dispensing of a metered dose of liquid product, and which minimizes the possibility of liquid product from being returned back to a supply container from within the dispenser accumulator.